How to determine the common-mode inductance of a switching power supply by its resistance value 2

In practical applications, the selection and evaluation of common-mode inductors require consideration of the following key parameters:

1. Impedance: The impedance value of a common-mode inductor is a key parameter for evaluating its effectiveness in suppressing common-mode noise. The impedance is typically measured at a specified frequency, such as 100kHz. diode

2. Rated Current: The common-mode inductor must be capable of withstanding the maximum current passing through it without causing overheating or core saturation.diode

3. DC Resistance (DCR): Low DC resistance helps reduce power loss and improve efficiency.

4. Insulation Resistance: Insulation resistance reflects the insulation effectiveness between the windings and the magnetic core of a common-mode inductor.

5. Operating Frequency Range: The common-mode inductor must function effectively within the specified operating frequency range.

6. Temperature Characteristics: The common-mode inductor must maintain stable performance within the operating temperature range.

7. Package and Size: Select the appropriate package and size based on the application scenario.diode

To evaluate the performance of common-mode inductors, parameters such as impedance curves, DC resistance, and saturation current are typically measured using inductance testing instruments, rather than relying solely on resistance values. When designing switching power supplies, engineers select appropriate common-mode inductors based on application requirements and conduct practical circuit tests to ensure the inductor effectively reduces EMI, thereby meeting relevant electromagnetic compatibility (EMC) standards.diode